鼻咽癌乏氧区MRI影像组学特征分析

目的 分析鼻咽癌乏氧区MR图像中影像组学特征,为乏氧区识别和分析提供参考。方法 回顾分析32例初诊鼻咽癌患者¹⁸F-FMISO-PET图像和短期内获得的MRI T1、T2、T1+图像。在MR图像勾画GTV,以4h的PET图像为依据勾画乏氧区域(GTV-H),将GTV减乏氧区定义为非乏氧区(GTV-NH)。提取GTV-H与GTV-NH影像组学特征,比较二者影像组学特征在不同MRI序列图像中差异。结果 GTV-H平均值为(10.92±11.02) cm³,GTV-NH平均值为(7.21±5.70) cm³。GTV-H与GTV-NH在MRI-T1中的灰度强度中全域最小值(ID-GM)获得的最大变化率为46%(P<0.05、AUC>0.7、约登系数>0.5);在MRI-T2中的灰度游程矩阵长游程因子(LRE)、长游程高灰度因子(LRHGLE)、长游程低灰度因子(LRLGLE)平均变化率达136%(P<0.05、AUC>0.7、约登系数>0.5);在MRI-T1+中的ID-GM、LRE、LRHGLE、HRLGLE变化率>90%(P<0.05、AUC>0.7、约登系数>0.5)。结论 MRI部分影像组学特征可客观反映鼻咽癌肿瘤靶区乏氧区域,量化和追踪这些特征变化有利于对鼻咽癌乏氧区域的识别。

Analysis of MRI radiomic features of hypoxic area in nasopharyngeal carcinoma patients

Objective To analyze the magnetic resonance imaging (MRI) radiomic performance of hypoxic area in nasopharyngeal carcinoma patients, aiming to provide a reference for identification and analysis of hypoxic area. Methods The MRI-T1, MRI-T2, MRI-T1+ and PET/CT images of 32 patients initially diagnosed with nasopharyngeal carcinoma were retrospectively analyzed. The gross tumor volume (GTV) of nasopharynx was countoured and the hypoxic areas (GTV-H) were identified by ¹⁸F-FMISO-PET images. The non-hypoxic areas (GTV-NH) were defined as the rest of areas removed GTV-H from GTV. The radiomic features of GTV-H and GTV-NH were extracted and compared. Results The average volume of GTV-H and GTV-NH was (10.92±11.02) cm³ and (7.21±5.70) cm³,respectively. The maximum rate of change was 46% for intensity direct-global min (ID-GM) on MRI-T1(P<0.05,AUC>0.7 and Youden index>0.5). The average rate of change was 136% for long run emphasis (LRE),long run high gray level emphasis (LRHGLE) and long run low gray level emphasis (LRLGLE) on MRI-T2(P<0.05,AUC>0.7 and Youden index>0.5). The high change rates was greater than 90% on MRI-T1+(P<0.05,AUC>0.7 and Youden index>0.5) for ID-GM,LRE,LRHGLE and LRLGLE. Conclusions The hypoxic area of tumor target can be reflected by MRI radiomics on T1/T2/T1+. Quantifying and tracking the variations of these features can bring benefit to recognize the hypoxic area of nasopharyngeal carcinoma tumor target.